General resins such as polyethylene (PE), polypropylene (PP), polyurethane (PU), polyvinyl chloride (PVC) and polycarbonate (PC) are used in various industrial fields such as living things, home appliances, cloths, vehicles, construction and packing materials because of excellent physical properties thereof.
Among them, polycarbonate is generally aromatic polycarbonate using bis-phenol A, but the use of aliphatic polycarbonate for improving physical properties of aromatics is apt to increase. Particularly, examples of aliphatic polycarbonate receiving attention as environmentally-friendly polycarbonate include polypropylene carbonate manufactured by copolymerization of propylene oxide (PO) and carbon dioxide and polyethylene carbonate manufactured by copolymerization of ethylene oxide (EO) and carbon dioxide through a similar reaction path, and in order to improve mechanical properties thereof, a terpolymer additionally using cyclohexen oxide, glycidyl ethers, glycidyl esters or the like in addition to propylene oxide and ethylene oxide has been developed and applied.
The polyvinyl chloride resin, the polyurethane resin, the epoxy resin or the polycarbonate resin may provide various processing physical properties by appropriately adding various additives such as a plasticizer, a stabilizer, a viscosity controlling agent, an internal release agent and a pigment, and the plasticizer among the additives is an essential additive added to the resins to provide various physical properties and performances such as processability, flexibility and adhesive property.
Volatility of the plasticizer should be very low, and performance of the plasticizer is continuously shown while a plastic composition is shaped by using the resins and the shaped products are used in practice, such that the plasticizer is very important in view of maintenance of physical properties. Further, the plasticizer provided to be applied to food and medical fields and the purpose of contact with human body should be harmless in view of health, and in the case of interior materials for construction, discharging of a volatile organic compound should be delayed.
Until now, examples of the plasticizer used for this purpose may include dialkyl phthalates, and particularly, it is known that dibasic esters such as ester compounds of citric acids or dioctyl adipates may be used as polycarbonates. However, it is expected that use of dialkyl phthalate will be significantly reduced because there is a controversy over regenerated toxicity under the law regulating toxic materials regarding stability of human body, and particularly, in the case of polypropylene carbonate or a copolymer of polyethylene carbonate and glycidyl ether or glycidyl ester thereof, since plasticity of the plasticizer such as dialkyl phthalate or dibasic esters is not sufficient, when the content of the plasticizer is low, such as, 10% or less, it is difficult to sufficiently reduce a glass transition temperature, and the use content should be high in order to ensure sufficient flexibility, but in this case, there is a problem in that surface stickiness after the resin composition is processed is increased. Further, since physical properties such as mechanical properties, flexibility at low temperatures, compatibility and durability of the plasticizer need to be improved, there is an urgent demand for developing a plasticizer improving this.